1. Field of the Invention
The present invention relates to a poke-through wiring device and, more particularly, relates to a self-anchoring poke-through wiring device which is positioned in a floor aperture of a concrete building floor for conducting electrical power and telecommunication signals between the work spaces of multi-storied buildings.
During the erection of building structures of various types; for instance, such as modern multi-storied office buildings possessing concrete floors, it is frequently necessary, and also commonly accepted practice, to normally provide fire-rated poke-through fittings and devices for conducting insulated conductors, wires, cables and the like for electrical power and telecommunication signals through holes or apertures which are formed in concrete building floors, and which electrical power and other kinds of signals, such as telecommunication signals, may be readily transmitted from a suitable source; for instance, a junction box located at or proximate one face of the concrete floor by means of the poke-through fitting through the aperture in the concrete building floor to a suitable outlet or service head which is located at the opposite face of the floor.
Hereby, in order to accomplish the foregoing purpose in positioning a feed-through fitting of the type described herein, and which has a poke-through fire barrier provided thereon within the aperture formed in the concrete floor, to be able to pass the insulated conductor or conductors through the fitting and fire barrier from one face of the floor to the other face of the floor, and to produce suitable connections in an electrical outlet or service head which is mounted over the aperture in the floor, generally the top face of the floor; the poke-through device may be equipped with gripping structure enabling the poke-through wiring device to be inserted from above into the floor aperture formed in the concrete floor and to resultingly anchor itself in a predetermined orientation in the aperture, while suspending a junction box below the floor aperture, as may be required. Consequently, the capability of being able to introduce the poke-through wiring device or fitting into the floor aperture from above and to enable it to be anchored in a predetermined oriented position in the aperture eliminates the need for cooperating electricians of working in tandem on the floors above and below the floor aperture in order to obtain an appropriately oriented installation of the poke-through fitting, thereby significantly reducing attendant labor costs.
2. Discussion of the Prior Art
In order to accomplish the foregoing; in essence, to provide the self-anchoring of the poke-through fittings or wiring devices or fitting it has heretofore been contemplated, in one specific instance, to compress fire-resistant discs, such as are made from an intumescent material, between two metal plates in a sandwich structure, and to thereby squeeze the intumescent discs so as to expand radially outwardly into contact with the perimeter of an aperture wall in a concrete floor to thereby securely retain the fittings therein. Although that type of structure imparts a self-anchoring feature to the fittings, it does not facilitate orienting the fittings in their extended angular positions so as to enable installing the wiring devices or poke-through fittings without the need for cooperating electricians working on opposite floors. Device of that type are described in Carroll, et al. U.S. Pat. No. 4,272,643.
An anchoring structure for poke-through wiring devices or fittings of the type considered herein is set forth in Shine U.S. Pat. No. 4,323,724, in which, fastened to a fire-retarding intumescent disc assembly, a split notched, ring-shaped resilient dished spring washer has anchoring surfaces adapted be wedged against the perimeter wall surface of a concrete floor aperture so as to securely anchor the entire poke-through wiring device or fitting therein in a predetermined angular orientation relative to the axis of the aperture. Although the fitting as elucidated in this patent publication imparts an essentially adequate self-anchoring feature to the poke-through fitting, in order to be able to remove the fitting from its installed position in the concrete floor aperture, this necessitates the entire fitting having to be forcibly pulled out, thereby practically either completely destroying or seriously damaging structural components thereof, necessitating expensive replacement thereof, in addition to entailing high labor costs in installing a new poke-through fitting. Moreover, the utilization of a resilient anchoring element, such as the dished spring washer, fails to secure the wiring fitting against upward displacement in the floor aperture, inasmuch as the anchoring force exerted outwardly against the wall surface of the floor aperture may be inadequate to ensure a permanent anchoring for the wiring fitting.
Another structure for the anchoring of a poke-through wiring device or fitting in a concrete floor aperture is described in Spencer U.S. Pat. No. 4,496,790, wherein a pair of substantially diametrically oppositely arranged resilient clips protrude beyond the diameter of a fire retarding plate-sandwich structure of a poke-through fitting on which they mounted by means of screw fasteners so as to contact, in a gripping manner, the perimeter of an aperture wall formed in a building floor which is constituted of a concrete material, thereby enabling the device to anchor itself in a predetermined angular orientation upon insertion therein, while facilitating removal and repositioning of the fitting through loosening of the screw fasteners and, resultingly, of the clips.
However, although the foregoing anchoring structure incorporating resilient clips improves upon the structure described in Shine U.S. Pat. No. 4,323,724 by enabling the clips to be removed through the loosening of the screw fasteners, and enabling the repositioning of the fitting subsequent to its being withdrawn from the floor aperture, the utilization of resilient clips which are of an essentially V-shaped configuration and in which the freely-flexible clip leg portion of the V-shape contacts the concrete wall fails to provide for an adequate gripping engagement with the wall of the concrete floor aperture, since the considerable flexibility and delicate nature inherent to this particular clip design does not allow for the exertion of a strong radial gripping force to be produced by this anchoring structure of the poke-through wiring device.